Home • About Us • A-Z Index • Search * Contact Us • Register • Login • Press • Shop

The Open Brand -- Problem Reporting and Interpretations System

Problem Report 1059 Details

Help Show help | Quick Search | Submit a Test Suite Support Request | Click here to view your privileges

This page provides all information on Problem Report 1059.

Report 1059 Actions

    Problem Report Number 1059
    Submitter's Classification Test Suite problem
    State Resolved
    Resolution Rejected (REJ)
    Problem Resolution ID REJ.X.0296
    Raised 1970-01-01 08:00
    Updated 2003-03-13 08:00
    Published null
    Product Standard Internationalised System Calls and Libraries Extended V2 (UNIX 98)
    Certification Program The Open Brand certification program
    Test Suite VSRT version 5.0.1
    Test Identification rt.os/timers/timer_settime 9
    Problem Summary PG4R.00008 Implementation reports values different from those produced by rounding.
    Problem Text

    The test case 9 has the following test assertion:

    If _POSIX_TIMERS is defined or the implementation sup-
    ports the timer_settime() function as described in Sys-
    tem Interfaces and Headers, Issue 5:

    A call to timer_settime() shall round up time values
    that are between two consecutive non-negative integer
    multiples of the resolution of the specified timer to
    the larger multiple of the resolution


    The cited text continues: Quantization errors shall not cause the timer
    to expire earlier than the rounded time value. Thus the topic of the
    paragraph is the relationship between the expiration of the timer
    and the underlying clock.

    The test case code interprets the standard that the time values
    that are rounded will be returned to the user when calls to timer_settime()
    and timer_gettime() are executed. The standard does state that the
    implementation shall do rounding.

    It does not state that the structures itimerspec value and ovalue passed to
    timer_settime() or timer_gettime() will contain or have the results of the
    rounding performed on the members of the structure.


    On page 947 of XSH5, the following paragraph to the one cited above:

    If the argument ovalue is not NULL, the function timer_settime()
    stores, in the location referenced by ovalue, a value representing
    the previous amount of time before the timer would have expired
    or zero if the timer was disarmed, together with the previous timer
    reload value. The members of ovalue are subject to the resolution
    of the timer, and they are the same values that that would be
    returned by a timer_gettime() call at this point in time.

    The standard does not state that the rounding of the interval
    will be returned. It does state that "...The members of ovalue are
    subject to the resolution of the timer..". The members of ovalue
    may have a result that combines a rounding and the time until
    the timer would have expired but not the explicit rounding for one
    interval.
    Test Output

    400|4 9 1 15:34:17|IC Start
    200|4 9 15:34:17|TP Start
    520|4 9 00000911 1 1|With resolution of 0 seconds, 1000 nanoseconds
    520|4 9 00000911 1 2|Expected value 0 seconds, 1001 nanoseconds
    520|4 9 00000911 1 3|To be rounded up to 0 seconds, 2000 nanoseconds
    520|4 9 00000911 1 4|Received 0 seconds, 10000000 nanoseconds
    520|4 9 00000911 1 5|With resolution of 0 seconds, 1000 nanoseconds
    520|4 9 00000911 1 6|Expected value 0 seconds, 999999001 nanoseconds
    520|4 9 00000911 1 7|To be rounded up to 1 seconds, 0 nanoseconds
    520|4 9 00000911 1 8|Received 0 seconds, 999999001 nanoseconds
    220|4 9 1 15:34:17|FAIL
    410|4 9 1 15:34:17|IC End

    Review Information

    Review Type TSMA Review
    Start Date null
    Completed null
    Status Complete
    Review Recommendation No Resolution Given
    Review Response
    We recommend this request be refused.

    This test validates the requirements of the spec as written while the
    implementation is producing inconsistent, inaccurate and non-conforming
    results.

    What's being tested here is the rounded-ness of the reload value returned
    by timer_settime. Since this reload value does not tick down it is a
    stable value to test, unlike the time until timer expiration, which is
    thus not covered by the test.

    The implementation has a 1000 nanosecond resolution. In the first
    case in the results above it returns 0 seconds, 10000000 nanoseconds
    for a relaod value set to 0 seconds, 1001 nanoseconds. This is neither
    the rounded up reload value, as the test expects, nor the original
    unrounded value, it just seems inexplicably wrong.

    In the second case the implementation returned 0 seconds, 999999001
    nanoseconds for a reload value set to the same value. Unlike the first
    case this behavior is the unrounded reload value. However we see nothing
    in the spec which justifies this behavior, as it does clearly require
    rounding by the implementation.

    The specification states:

    Time values that are between two consecutive non-negative integer
    multiples of the resolution of the specified timer will be rounded
    up to the larger multiple of the resolution.

    . . .

    <for timer_settime> The members of ovalue are subject to the
    resolution of the timer, and they are the same values that would
    be returned by a timer_gettime() call at that point in time.

    So, in checking the reload value returned by timer_settime the test is
    correctly expecting a rounded up value as a) the values returned by
    timer_settime are subject to the resolution of the timer, and b)
    values are rounded up if they are not a multiple of this resolution.

    Review Type SA Review
    Start Date null
    Completed null
    Status Complete
    Review Resolution Rejected (REJ)
    Review Conclusion
    This request is refused.

    Problem Reporting System Options:

     

    Back   

Contact the Certification Authority